Firstly, re-read the Sheldon article(s) just so you are totally clear.
There are wheels which have a threaded hub which accept a freewheel (ratcheting set of chainrings), or alternatively the later freehub system which has a cassette of separate chainrings fitted to a ratcheting mechanism which is already embedded in the hub.
The latter has the advantage of causing less stress on the axle and is probably preferable.
If I were you, I'd stick with 7-speed if it was a slight squeeze (sounds like you may have 120mm spacing). Freehub/cassette preferable, though not essential.
I'd look on eBay or post a WTB here for what you are looking for. Mavic make good rims in general, and I've had no trouble with Shimano, Ritchey, Mavic, and Campagnolo hubs.
If it's a sub 531 Raleigh frame, then I'd maybe be aiming to spend less than £30 on each wheel unless you want to use them for a later build.
Firstly, re-read the Sheldon article(s) just so you are totally clear.
There are wheels which have a threaded hub which accept a freewheel (ratcheting set of chainrings), or alternatively the later freehub system which has a cassette of separate chainrings fitted to a ratcheting mechanism which is already embedded in the hub.
The latter has the advantage of causing less stress on the axle and is probably preferable.
If I were you, I'd stick with 7-speed if it was a slight squeeze (sounds like you may have 120mm spacing). Freehub/cassette preferable, though not essential.
I'd look on eBay or post a WTB here for what you are looking for. Mavic make good rims in general, and I've had no trouble with Shimano, Ritchey, Mavic, and Campagnolo hubs.
If it's a sub 531 Raleigh frame, then I'd maybe be aiming to spend less than £30 on each wheel unless you want to use them for a later build.